This invention relates generally to road construction equipment and more particularly concerns equipment for reconstructing or recycling macadam roads and highways.
Macadam highways have been extensively built in recent years. In general, these highways are laid over a base which can include a substructure and in some instances a final course of concrete. In its upper strata, the highway includes a macadam top surface formed of stone or gravel aggregate bound firmly together by a bituminous bonding agent such as asphalt.
Such roads provide a relatively trouble-free, permanent surface. Inevitably, however, the passage of time and traffic and the impingement of weather causes this macadam surface to become brittle and crack. Where concentrated cracking occurs, pieces of pavement may become dislodged. This dislodgment can create traffic hazards, and accelerates the deterioration of adjacent pavement and the highway substructure. Even if cracking does not occur, the passage of traffic can polish the upper highway surface, and a polished, slippery highway surface may be dangerous.
In addition, traffic-caused wear can groove or trough a highway surface. Under wet highway conditions, water can collect in these troughs and set up dangerous vehicle hydroplaning phenomena.
Repairing these deteriorated highways and roads can be an expensive and difficult task. Road resurfacing apparatus used to reconstruct or recycle these highways are disclosed in U.S. Pat. Nos. 3,361,042, 3,724,445, 3,807,886 and 3,874,366. While these devices have met with commercial success, it has until now proved impractical to physically remove and rejuvenate recycle the upper macadam strata of deteriorated highways.
It is accordingly the general object of the present invention to provide apparatus for recycling macadam highways, airport runways or the like. A related object is to provide such apparatus which will accomplish this recycling activity rapidly and at minimum cost.
Another object is to provide highway recycling apparatus which will provide a new, smooth, crack-free, safe and long lasting highway surface.
Another object is to provide apparatus for repaving a macadam highway which uses, as a major ingredient of the new pavement, the original deteriorated highway pavement material.
Yet another object is to provide recycling apparatus which minimizes labor requirements.
Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings. Throughout the drawings, like reference numerals refer to like parts.